FIL and I have built ARs together in the past and he is wanting to build a 10/22 w/ aftermarket parts.  I've looked at receivers, trigger assemblies, bolts, barrels  & stocks.  What are some of the other internals I need to look into?  

For the record, I've shot plenty of 10/22s, but have no experience w/ tearing them down or their inner-workings.  FIL has a few 10/22s, but wants to build one from the ground up.  I'm likely going to start w/ a Nodak Spud receiver w/ some Kidd/Volquartsen/TI internals.

Mine is all Kidd save the receiver.  In retrospect, it would have been cheaper for me to just buy the complete rifle from Kidd.

Yep, I don't see myself or the FIL buying a ton of the pricier parts from Kidd or Volquartsen for our first builds. Maybe on the inevitable second one.

It's apparently cheaper to build from 597 parts.

I did mine with a NoDak spud receiver.

Personally I would go with a KIDD Classic receiver. IMO they are the best receivers out there and also a smoking deal at $152 considering that it comes with a scope rail included(0,10 or 20MOA). I believe the Nodak with a rail runs around $200.

One killer feature of the KIDD Classic is the optional rear tang. It requires some minor stock modification(great detailed instructions over at RimfireCentral.com) but is well worth it. What it does is add a second takedown screw behind the receiver. One of the flaws in the 10/22 design(IMO of course) is the single takedown screw in the middle of the action. If you don't have upward pressure somewhere under the barrel, the action will teeter-totter in the stock which basically means you can't fully free float the barrel which is important if you're looking for every bit of accuracy. The rear tang is the perfect solution to the single takedown screw and gives you the most solid action to stock connection possible. It really makes a big difference in my experience.

Rear tang on my KIDD visible here-

Don't waste your money on anything other than KIDD.  KIDD is pricey, but hands down best 10/22 parts available.

Yep, you should absolutely go for something with a tang. I've had problems with my factory gun shifting around in the stock.

The original design really should have had two takedown screws.

Goodluck with your build I always look forward to seeing more budget builds

There are several good options for bolts and receivers.

I have both a VQ trigger group and a KIDD trigger group. In all fairness I like the VQ trigger a little better. (Burn the heretic!)

I really like the  KIDD rear tang. I have them on all 3 of my 10/22's

Well well.  Looks like we'll both be getting the KIDD receivers + tangs.  Just came back into stock and on sale for $20 off.

Any advice on inletting the stock to accept the rear tang?  Still uncertain on what stock I'm after.  Like the Boyd Tacticool/Pro Varmint, but am also eying the TacSol stocks that are already bedded in the front.

Yea buts it's a lot fun...
I have a NIB 10/22 that's sayin KIDD Me.

Yessir you are correct it prolly would have been cheaper.
I took a brand new 10/22, removed everything crept the receiver.
Then replaced with all Kidd stuff. It's a tack driver at 50.. Depends on the wind at 100yd

Here's a good thread on installing a rear tang-
http://www.rimfirecentral.com/forums/showthread.php?t=477781

Another good one-
http://www.primalrights.com/forum/viewtopic.php?f=30&p=27809